Influence of the thyroid state on myocardial myosin in the adult pig heart

Wiegand, V.; Henniges, H.; Oberschmidt, R.; Kreuzer, H

doi:10.1007/bf01906739

Cited by 7 publications

(1 citation statement)

References 23 publications

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“…It has also been reported that excessive thyroid hormone may induce tissue injury. Thyrotoxic myopathy (8) and myocardial insufficiency (9) are well known examples of tissue damage due to the direct action of thyroid hormone on target tissues. The pathophysiological basis of these abnormalities is not clear.…”

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confidence: 99%

Lipid Peroxidation and Free Radical Scavengers in Thyroid Dysfunction in the Rat: A Possible Mechanism of Injury to Heart and Skeletal Muscle in Hyperthyroidism*

et al. 1987

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This study was designed to determine if peroxidation of biomembrane lipid and the protective system can be modified by the change in oxidative metabolism induced by thyroid dysfunction. The free radical scavengers (i.e. cuprozinc cytosolic and mangano mitochondrial superoxide dismutases, glutathione peroxidase, and catalase), mitochondrial oxidative marker enzymes (cytochrome c oxidase and fumarase), and lipid peroxide were measured in liver, heart, soleus (slow oxidative), and extensor digitorum longus (fast glycolytic) muscles. Rats were rendered hyper- or hypothyroid for 4 weeks and then killed. Superoxide dismutases were detected by specific RIAs: catalase by polarography, and lipid peroxide by fluorimetry. Hypothyroid rats failed to grow, while hyperthyroid rats had hypertrophied hearts but no growth failure. An increase in lipid peroxide was observed in the soleus and heart muscles of hyperthyroid rats. This was accompanied by an increase in mitochondrial superoxide dismutase and oxidative markers. No such change was observed in either fast glycolytic muscle or liver. Glutathione peroxidase decreased in all tissues of hyperthyroid rats, and there was a parallel decrease in catalase in most tissues. On the other hand, hypothyroidism induced a reduction in oxidative markers and mitochondrial superoxide dismutase in heart and skeletal muscles, but only a marginal change in lipid peroxidation. The cytosolic superoxide dismutase did not change in relation to either oxidative metabolism or lipid peroxidation. These results suggest that the enhanced oxidative metabolism and decreased glutathione peroxidase in hyperthyroidism result in an increase in lipid peroxidation and, in slow oxidative and heart muscle, possible organ damage. No adverse reaction mediated by active oxygen species was found in hypothyroid rat tissues.

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confidence: 99%

Lipid Peroxidation and Free Radical Scavengers in Thyroid Dysfunction in the Rat: A Possible Mechanism of Injury to Heart and Skeletal Muscle in Hyperthyroidism*

et al. 1987

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Structure and function of contractile proteins in human dilated cardiomyopathy

Wiegand

Ebecke

Figulla

et al. 1989

Clinical Cardiology

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Summary: The pathogenesis of reduced systolic left ventricular function in dilated cardiomyopathy is yet unclear. To analyze a possible involvement of contractile protein, function and structure of left ventricular myofibrils were examined in hearts of patients with advanced cardiomyopathy undergoing heart transplantation and in normal control hearts (from renal transplant donors). Myosin and actin content of the left ventricular myocardium was slightly reduced in cardiomyopathic hearts. Myofibrillar polypeptide composition was determined using twodimensional electrophoresis and immunoblotting . No differences in constituting polypeptides were apparent, including Z-line proteins and proteins of the endosarcomeric lattice. M-line-bound creatine kinase was identical in both groups. Further, basal and maximal myofibrillar adenosine triphosphatase (ATPase) activities were unaltered in dilated cardiomyopathy. The structure of purified myosin was identical in both groups by the following criteria: electrophoretic mobility of native myosin, identical pattern of light chains after isoelectric focusing, identical cleavage peptides of myosin's heavy chain, and identical patterns after immunoblotting of heavy chain cleavage peptides using polyclonal antibodies generated against myosin from normal and cardiomyopathic ventricles. Ca2+-activated, K'-EDTA-activated and actin-activated myosin ATPase activities were identical in control and cardiomyopathic hearts. A structural alteration or functional defect of myofibrils does not seem to be primarily involved in the pathogenesis of reduced myocardial contractility in dilated cardiomyopathy .

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